This application claims the benefit of Korean Patent Application No. 1999-28065, filed July 12, 1999.
1. Field of the Invention
The invention relates to methods and apparatus for purifying contaminated air, and more specifically to methods and apparatus for forming a liquid filter using centrifugal force that is applied to the liquid to eliminate contaminants and for absorbing, diluting, dissolving, and disassimilating harmful objects in the air using a multi-stage air purification process.
2. Related Art
An air purifying device can be used, for example, in a ventilation system or in an air treatment facility. A primary function of an air purifying device is to reduce the amount of contaminated materials and objects harmful to human health to a level that is healthy.
There are generally three techniques of purifying air. One is the usage of a particulate or adsorption filter. Such a filter having a fixed shape can be placed within a duct or channel which transfers air. Particulate or adsorption filters can be of many different shapes, sizes, and forms. Materials commonly used in these filters include, among others, glass fiber, cellulose paper, cotton, polyurethane, and other synthetic materials. The basic operating principles of particulate or adsorption filters are to capture particles that are larger than the gaps in the filters and block them from passing through the filters, to capture the particles using an adhesive force that is created when the particles collide with the surface of the fibers, and to capture small particles by moving the particles in a direction which causes more collisions between the fibers and particles.
A second technique uses a sprayer. A sprayer can be installed to eject water within a duct or channel which transfers air. The basic operating principles of a sprayer is to capture the contaminants in the air using fine liquid particles and to control humidity simultaneously. Recently, high pressure pumps have been employed to eject ultra-fine liquid particles that are quickly evaporated providing cooling.
A third technique uses an electrostatic air filter. Such a filter can be installed within a duct or channel which transfers air. An electrostatic air filter first passes dirty air between ionizing wires which are at a high voltage. Electrons are stripped from the particulate contaminants, leaving them positively charged. Then, these ionized particles pass between collector plates that are closely spaced and oppositely charged. The particles are simultaneously repelled by the positive plates and attracted to the negative plates, where they are collected.
A filter selection can depend on, among others, the required level of cleanliness, the installation location, and cost. While a particular type of filter can be used by itself, various types of filters are often combined to increase the efficiency.
Existing air purification filter systems have significant disadvantages. First, particulate filters need regular cleaning, maintenance, and replacement. In addition, the contaminants removed by the filters and used filters become another origin of contamination. Secondly, a sprayer requires constant ejection of water to eliminate contaminants in the air, resulting in excessive usage of water. A sprayer further requires a device to collect the water used and a system to treat the contaminated water. Thirdly, an electrostatic air filter requires a complex electronic device, and its initial installation cost is high. In addition, it is debated as to whether the ions produced by electrostatic air filters are harmful to people.
The invention provides a simple mechanical structure and a simple air purifying process to overcome the disadvantages of prior art air purifying systems. The maintenance and operational costs of an air purifying system of the invention are significantly lower than those of existing air purifying systems. In addition, the invented system can achieve a higher degree of purification efficiency in comparison with that of existing air purifying systems.
The invention has the following advantages: First, because the air purifying system of the invention utilizes a simple mechanical structure and a simple purifying method, various costs associated with the invented system such as the manufacturing cost, maintenance cost, and operational cost are significantly lower than those of existing air purifying systems. The invented system is highly economical in terms of, among others, maintenance and operation. Second, the invented system can provide various air purifying capabilities using centrifugal force and can purify air in multi-stages. As a result, the invented system can achieve a higher degree of purification efficiency in comparison with that of existing air purifying systems.